玉林市“4·19”飑线大风成因及雷达特征分析  

Analysis of the causes of gale and radar characteristics of“4·19”squall line in Yulin

作　　者：张容菁 李秀昌 彭武坚 林确略 陆秋霖 ZHANG Rongjing;LI Xiuchang;PENG Wujian;LIN Quelue;LU Qiulin(Yulin Meteorological Bureau,Guangxi Yulin 537000,China)

机构地区：[1]玉林市气象局,广西玉林537000

出　　处：《气象研究与应用》2023年第3期90-94,共5页Journal of Meteorological Research and Application

基　　金：广西气象青年人才培养项目(桂气科2023QN13);广西气象科技计划指令性项目(桂气科2023ZL11)。

摘　　要：利用自动气象站加密和常规观测资料、欧洲中期天气预报中心全球气候第五代大气再分析数据(ERA5)以及SA波段双偏振雷达资料,对2023年4月19日玉林暖区飑线过程进行分析。结果表明:(1)本次飑线过程发生在高空短波槽、低空切变线和地面倒槽锋面影响的环流背景下,是一次湿对流型飑线。(2)中层短波槽的动力作用与低层高温高湿环境配合较好,倒槽中的锋面是触发强对流天气的关键系统,飑线成熟阶段,受中高层短波扰动影响,飑线脱离锋面向暖区快速移动发展。(3)此次暖区飑线过程具有飑中系统的典型特征,飑线后部形成一个冷池,冷池密度流形成强的雷暴出流,造成冷池前部玉林多处出现10级以上大风。(4)雷达回波具有弓状回波、速度模糊、后侧入流缺口等雷暴大风特征,双偏振参量显示ZDR大值区随高度降低,回波均一性较好(CC>0.9),ZDR和KDP都可以看到飑线前沿的极大值窄回波带。Based on data from automatic weather stations,conventional observations,ERA5 reanalysis data,and dual-polarization radar data,the squall line event in the Yulin warm sector that occurred on April 19,2023 was analyzed.The results show that:(1)The squall line event occurred under the influence of the upper-level shortwave trough,low-level shear line,and surface inverted trough front,indicating it is a moist convective squall line.(2)The dynamic effect of the mid-level shortwave trough,in conjunction with the warm and moist environment in the lower levels,played a significant role.The front within the inverted trough was the key system triggering severe convective weather.During the mature stage of the squall line,influenced by the mid-to upperlevel shortwave disturbance,the squall line detached from the front and rapidly developed towards the warm sector.(3)This warm sector squall line event exhibited typical characteristics of a squall system.A cold pool formed behind the squall line,and the density currents associated with the cold pool generated strong thunderstorm outflows.As a result,Yulin experienced gale above magnitude 10 on the Beaufort scale in multiple locations ahead of the cold pool.(4)The radar echoes exhibited characteristics of severe thunderstorm gale,such as bow echoes,velocity aliasing,and rear inflow notches.The dual-polarization parameters showed a decrease in the ZDR(differential reflectivity)maximum values with height,indicating a narrowing echo band with good echo uniformity(CC>0.9).Both ZDR and KDP(specific differential phase)showed the presence of a narrow band of maximum values along the leading edge of the squall line.

关 键 词：暖区飑线 大风 环境条件 双偏振雷达回波 

分 类 号：P458.123[天文地球—大气科学及气象学]